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Diffstat (limited to 'compiler/GHC/Tc/Utils/Unify.hs')
| -rw-r--r-- | compiler/GHC/Tc/Utils/Unify.hs | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/compiler/GHC/Tc/Utils/Unify.hs b/compiler/GHC/Tc/Utils/Unify.hs index a6711abcc1..75f4e83979 100644 --- a/compiler/GHC/Tc/Utils/Unify.hs +++ b/compiler/GHC/Tc/Utils/Unify.hs @@ -622,7 +622,7 @@ tc_sub_type unify inst_orig ctxt ty_actual ty_expected where possibly_poly ty | isForAllTy ty = True - | Just (_, res) <- splitFunTy_maybe ty = possibly_poly res + | Just (_, _, res) <- splitFunTy_maybe ty = possibly_poly res | otherwise = False -- NB *not* tcSplitFunTy, because here we want -- to decompose type-class arguments too @@ -746,7 +746,8 @@ to a UserTypeCtxt of GenSigCtxt. Why? -- only produce trivial evidence, then this check would happen in the constraint -- solver. tcSubMult :: CtOrigin -> Mult -> Mult -> TcM HsWrapper -tcSubMult origin (MultMul w1 w2) w_expected = +tcSubMult origin w_actual w_expected + | Just (w1, w2) <- isMultMul w_actual = do { w1 <- tcSubMult origin w1 w_expected ; w2 <- tcSubMult origin w2 w_expected ; return (w1 <.> w2) } |